What are the expected developmental milestones for a 6-month-old well child?

6-Month Well Child Developmental Milestones

At 6 months of age, infants should demonstrate rolling from prone to supine, supporting themselves on elbows and wrists in prone position, lifting head and chest when prone, keeping hands unfisted most of the time, playing with fingers at midline, and grasping and reaching for objects. 1, 2

Gross Motor Skills

By 6 months, the following motor milestones are expected:

• Rolling over from prone to supine position is a key milestone that should be achieved 1, 2
• Supporting weight on elbows and wrists when placed on stomach demonstrates appropriate upper body strength 1, 2
• Lifting head and chest when prone shows adequate neck and trunk control 1, 2

Important caveat: Infants who sleep primarily in supine or side positions may achieve rolling later than those who sleep prone, though this does not necessarily indicate pathology 3. However, absent rolling at 6 months warrants close monitoring, and absent rolling at 7 months requires urgent comprehensive neuromotor examination 1.

Fine Motor Skills

At 6 months, fine motor development includes:

• Hands should be unfisted most of the time, indicating normal tone and motor control 1, 2
• Playing with fingers at midline demonstrates bilateral coordination 1, 2
• Grasping and reaching for objects shows appropriate hand-eye coordination 1, 2

Note that the pincer grasp is not expected until 9-12 months, so its absence at 6 months is not concerning 1.

Social-Communication Development

Social milestones are equally important at this age:

• Social smiling, eye contact, and early social engagement should be well-established 2
• Response to social stimuli with positive affect during interactions is expected 2
• Early vocalizations and prespeech sounds should be present 2

Developmental Surveillance Approach

The American Academy of Pediatrics recommends continuous developmental surveillance at every well-child visit, though formal standardized developmental screening is not scheduled until 9 months 4, 1, 5. At the 6-month visit, clinicians should:

• Elicit and document parental concerns about development, as parent concern is valid reason to trigger formal investigations 1
• Make accurate observations of spontaneous motor function by watching posture, play, and movement without stressful performance demands 1
• Identify risk and protective factors in the child's history 1
• Document developmental history comprehensively 1

For infants born before 36 weeks' gestation, correct for prematurity for at least the first 24 months when assessing milestones 1, 2.

Critical Red Flags Requiring Immediate Action

The following findings at 6 months warrant urgent evaluation and referral:

• Regression or loss of any previously acquired motor skills is a major red flag requiring immediate evaluation for progressive neuromuscular disorders 1, 2
• Inconsistent head control in prone position suggests possible weakness or abnormal tone 1
• Hypotonia (floppiness or decreased muscle tone) indicates higher urgency for subspecialist referral 1
• Dysmorphic features warrant earlier subspecialist referral 1
• Marked asymmetry in movement patterns may indicate unilateral cerebral palsy and requires immediate evaluation 1

When to Refer

If motor delays are identified at 6 months, immediate referral to early intervention services and concurrent referral to pediatric physical therapy and pediatric neurology is recommended 1. Key principles include:

• Do not wait for subspecialist appointments to initiate therapy services—refer to physical therapy while diagnostic investigations proceed 1
• All children with suspected motor delay should be referred to early intervention immediately, even before a specific diagnosis is established 1
• Early intervention services should be activated within weeks, not months 1
• Direct physician-to-physician communication is recommended when motor delays are identified 1

Cerebral palsy can be accurately diagnosed before 6 months' corrected age using validated tools with 86-98% sensitivity, making early identification critical for optimizing long-term outcomes 1.

Common Pitfalls to Avoid

• Do not adopt a "wait and see" approach when motor concerns are present—early intervention improves outcomes regardless of final diagnosis 1
• Do not dismiss parental concerns even when clinical observations seem reassuring 1
• Do not delay therapy referrals while awaiting diagnostic clarity—children benefit from therapy regardless of whether a specific neuromotor diagnosis has been identified 1
• Remember to correct for gestational age in premature infants, as failure to do so may lead to inappropriate concern or false reassurance 1, 2